1. Field of the Invention
The present invention relates to a color filter substrate, and more particularly, to a color filter substrate with wider spacing between dummy color filter units or wider spacing between a color filter unit and the dummy color filter unit.
2. Description of the Prior Art
Electronics, such as televisions, cell phones, mobiles, and refrigerators, often include flat display panels. The liquid crystal display (LCD) panel has become the mainstream flat display panel because of its great display performance and low cost. Generally, the LCD panel includes an array substrate, a color filter substrate, and a liquid crystal layer sandwiched in-between the two substrates. The array substrate includes a plurality of array pixel units for driving liquid crystal molecules in the liquid crystal layer. The color filter substrate includes a plurality of color filter units for displaying different colors.
Please refer to FIGS. 1-2. FIGS. 1-2 are schematic diagrams partially illustrating the color filter substrate according to a prior art. FIG. 1 is a top-view diagram, and FIG. 2 is a cross-sectional view diagram taken along a cross-sectional line P-P′ in FIG. 1. As shown in FIGS. 1-2, a color filter substrate 900 includes a substrate 90, a patterned light-shielding layer 91, a plurality of color filter units 92, a plurality of dummy color filter units 93, an over-coating layer 94, and an alignment layer 95. The substrate 90 has a display region AA and a peripheral region DA. The peripheral region DA surrounds the display region AA. The patterned light-shielding layer 91 is disposed on the substrate 90. The patterned light-shielding layer 91 includes a first light-shielding pattern 91A disposed on the display region AA and a second light-shielding pattern 91B disposed on the peripheral region DA. The first light-shielding pattern 91A defines a plurality of sub-pixel regions PX. The color filter units 92 are disposed on the display region AA, and each of the color filter units 92 is disposed correspondingly to each of the sub-pixel regions PX and partially overlaps the first light-shielding pattern 91A. The dummy color filter units 93 are disposed on the peripheral region DA, and the second light-shielding pattern 91B is disposed under the dummy color filter units 93 on the peripheral region DA. The dummy color filter units 93 and the color filter units 92 are formed by the same manufacturing process. The dummy color filter units 93 are employed for improving the display quality around a border between the display region AA and the peripheral region DA. In addition, in order to improve the display quality by inhibiting the phenomenon of light leakage, the second light-shielding pattern 91B has to be large enough to completely block each of the dummy color filter units 93 as viewed in a direction Z normal to the substrate 90. After forming the color filter units 92 and the dummy color filter units 93, the over-coating layer 94 and the alignment layer 95 are sequentially formed to cover the substrate 90, the patterned light-shielding layer 91, the color filter units 92, and the dummy color filter units 93.
Generally, in consideration of production cost and process simplification, the color filter units 92 and the dummy color filter units 93 are formed by using an identical photomask. Therefore, a width W93 of each of the dummy color filter units 93 is equal to a width W92 of each of the color filter units 92, and spacing P93 between two adjacent dummy color filter units 93 is equal to spacing P92 between two adjacent color filter units 92, in addition, a thickness H93 of each of the dummy color filter units 93 is equal to a thickness H92 of each of the color filter units 92. Because the second light-shielding pattern 91B completely blocks each of the dummy color filter units 93 on the peripheral region DA and the over-coating layer 94 is not thick enough, a difference D9 in height between the over-coating layer 94 on the peripheral region DA and the over-coating layer 94 on the display region AA may be significant. A subsequent rubbing process on the alignment layer 95 may be seriously affected by the difference D9 in height around the border between the display region AA and the peripheral region DA, and defects such as light leakage may therefore occur.